HIF-1α Active Components of the Unstudied Plant, Crossosoma bigelovii

Crossosoma bigelovii (Crossosomataceae) is a deciduous shrub found sporadically throughout arid regions of southwest North America. To date, there are no published studies of the chemistry or medicinal properties of this plant. An organic extract of the aerial parts of the plant exhibited potent inhibition of HIF-1α transcriptional activity in high-throughput in-vitro screening. Scale-up chromatography of the extract led to the isolation and identification of a novel cardenolide diglycoside as the HIF-1 active compound. Purification of other components from the active fraction uncovered the presence of the indole alkaloid ajmalicine, the chromone noreugenin, the dibenzylbutane lignan secoisolariciresinol, and the dibenzylbutyrolactone lignan matairesinol. Acknowledgements: Funded by NCI Contract N01-CO-12400. This research was supported [in part] by the Developmental Therapeutics Program in the Division of Cancer Treatment and Diagnosis of the National Cancer Institute. We gratefully acknowledge R. Spjut for collection of C. bigelovii.